1. Field of the Invention
The present invention relates to a wireless communication system provided with at least two handsets that connect wirelessly to a base unit. The system uses a wireless communication method that allows direct communications between handsets.
2. Description of the Prior Art
Cordless telephones that perform bi-directional communications between a base unit and handset are well-known in the art. In this type of cordless telephone, a handset receives data transmitted by a base unit at a frequency f1, and the base unit receives data transmitted by the handset at a frequency f2.
However, if two or more handsets are provided with one base unit, and the base unit is receiving signals from one handset at a frequency f2, for example, the base unit cannot receive signals from another handset at the frequency f1. Hence, communication between two handsets is not possible.
Further, cordless telephones that perform spread spectrum communications between a base unit and handset using a frequency hopping method are well-known in the art. In this type of cordless telephone, the frequency switching sequence (hereinafter referred to as "hopping pattern") used during communications is predetermined, and the base unit and handset always follow the same hopping pattern.
However, direct communication between two handsets has not been possible because of the possibility that such direct communication might conflict with control signals being transmitted from the base unit.